Picker stick checking mechanism and check strap therefor



March 5, 1957 A. FREEDLANDER 2,783,779

PICKER STICK CHECKING MECHANISM AND CHECK, STRAP THEREFOR Filed June 3, 195O 2 Sheets-Sheet 1 INVENTOR. All. FREEDLANDER W I ATT Y.

March 5, 1957 A. FREEDLANDER 2,783,779

PICKER STICK CHECKING MECHANISM AND CHECK STRAP THEREFOR Filed June 3, 1950 2 Sheets-Sheet 2 INI'ENTOR. A L. FREEDLANDER ATT'Y.

United States Patent 6 ice riCkER STICK cmzcrmvo MECHANISM ANT) CHECK STRAP THEREFOR Abraham Lincoln Freedlande'r, Dayton, Ohio, assignor to The Dayton Rubber Company,- a corporation of Ohio Application June" 3, 1950, Serial No. 165,990

2 Claims. (Cl; 139161) The present invention relates to picker stick checking mechanisms for fly shuttle looms, and more particularly'to novel check straps for use in such mechanisms. Picker stick checking mechanisms frequently include one or more'check'straps which may either be of the'endless variety or may be formed'in loops and attached at the open ends thereof. The endless type may be mounted so that the strap is passed between friction fingers or siiubbers to form an elongated loop, the ends of which engage the picker stick at opposite ends of its swing and serve to' check the momentum of the stick by means of sliding friction created by the friction fingers. In these constructions the picker stick moves at a high rate of speed and when the opposite ends of the loop are struck, the blow occurs repeatedly in thesame or substantially the" same area of the strap resulting in excessive strain arid undue wear. At the same time the strap rubs against the friction fingers along the same area of contact resulting in eiicessive wear in this area also;

Ih order to overcome these disadvantages it has been necessary either to replace the check straps frequently or to make them of anunduly heavy construction.

One object of the present invention is to provide a checking mechanism wherein excessive wear in localized areas of the check strap will be eliminated. An addi-' tio'nal object of the present invention is to provide a checking mechanism which will utilize an endless, unattached and freely moving check strap which will receive successive impacts of the picker stick over successively varyingportions of its surface. A further object of the present invention is to provide an improved check strap construction which will enable the check strap to rotate or move progressively between the friction fingers in such a manner that the strap will move in the same direction an 1increment of distance upon each impact of the picker 'stic In accordance with the present invention one or more endless check straps are mounted between snubbing fin gers to form a loop having a diameter somewhat less than the arc of movement of the picker stick. Therefore as the picker stick approaches the end of its stroke in returning from the shuttle throw, it will strike one end of the loop and its motion will be retarded through the actioii of the snubbing fingers between which the strap rides. On the throw of the shuttle as the picker stick approaches the end of the throwing motion its momenturn will be checked by the other end of the loop, also by the action of the snubbing fingers on the check strap. Applicant has discovered that if the inner surface of the check strap or if both the inner and outer surfaces of the check strap are formed with grooves, corrugations or "teeth extending transversely to the longitudinal axis or at an angle thereto, the impact of the picker stick will cause the check strap to move forward or in effect to rotate in one direction an increment of distance upon each blow of the stick. This results in a progressive rotation of the check'strap and presentation of a new surface of the strap to each successive blow. As a result, the wear 2,783,779 Patented Mar. 5, 1957 2: on the strap} hothdue to friction caused by the snubbers, and to the iiiipact 'o'f the picke'fstick', will be distributed uniformly overthe entire surface of the strap with resultant increase in its life. Instead'of a s'in'gle'strap of the pro er v'v'idtha plurality of separate straps arranged in superimposedrelationship"as'in the/patent to Hamilton No. 2,408,636 of Johnson No. 2,426,353,- may be 'utilized. This same type of progressive rotation does not appear; to dccur'iii the absence of the grooves referred to.

Havingthus' briefly described the invention and its objectives; it will nowbe described in' greater detail refereiice being had to theacc'oriip'anying drawings wherein the invention has been illustrated in its preferred forms andinwhichz' Figure 1 is a'plan view looking upward toward the bottom of 't'hela'y beam' and slotf'within which the picker stick moves illustrating the check strap construction sup ported betweensnubb'in'g fingers.

Figure 2 illustrates a longitudinal cross section taken along lines22 of Figure 1 illustrating the longitudinal structure of a novelcheck strap construction and showin'g'the grooved surface of the strap inelevation.

Figure 3 is a transverse cross 'section taken along lines 3 -3 of Figure 1 illustrating the internal construction of the novel check strap.

Figure 4'is a long'i tudinal cross section illustrating the internal construction of a modified form of the novel check straptakenalong a plane similar to that illustrated in 'Figure 2.

Figure 5' describesin'lo'n'gi'tudinal cross'section the structure oranaurastivererm ofthe check strap taken along thes'atrie plan'eas' Figure 2;

Figure 6 isfa side" elevation or one form of a checking mechanism-of-theinvention'utilizing'a single check strap.

Figure? is aside elevation of another'form of a checkiiigniechanisiii utilizing a'plurality of superimposed check straps.

Referringnow td-Figure l,-reference numeral 10 repres'entsthelaybeam defining slot'll between which pickei s'tiok- 1'2 showr'i'incross section moves. Brackets 13 and 14 are mounted on the opposite sides of the lay beam and are formed with a plurality of depending fingers or snubbers which are arranged in 'a staggered manner as shown. Fingers 15, 16 and 17 are positioned on one side of the slot and fingers 15a, 16a and 17a are positioned adjacent theother'side of the slot. These-fingers are formed with transverse projections so that the check strap 18 will be supported thereon as illustrated. The check strap is formed with spaced corrugations extending' over the entire inner surface as well as the entire outer surface, as hown. Preferably, s'n'ubberpins 16 and 16a are laterally adjustable in slots 19 and 19a to increase or decrease the amount of friction applied to the check strap. In some cases, asingle'set of fingers may be mounted at one side of the slot, the other side of the loop being supported in any desired manner.

When the picker stick approaches the return portion of its stroke it engages the check strap and its motion is rctarded by the action of the snubbers as the check strap is moved to the position shown in Figure 1. During the throwing portion of its stroke the picker stick'will engage the opposite end of the loop pulling it between the snubbers and driving it in the opposite direction. The check strap of the present invention as illustrated in Figu'res 2 and 3 is formed with transverse grooves or corrugations 20 in the outer surface and 21 in the inner surface. These corrugations are, distributed over the entire inner and outer surfaces in a spaced manner. The preferred construction will utilize parallel longitudinally extending cords 22 embedded in or between layers of rubber 23 and 24 and havingtop and bottom fabric layers 25 and 26; 'Upon each blow of" the stick, in either direction, it has been found that with the corrugated or grooved construction described herein, the check strap will move forward a small increment of distance. As a result, successively new surfaces are presented to successive blows of the stick, thus permitting much greater life of the strap. In general, the direction of movement will depend on the plane in which the picker stick moves and the rate of movement will depend on the extent of deviation of the stick from the absolute vertical plane.

The check strap may be made as follows: A drum or mandrel having a diameter corresponding to the desired inner diameter of the check strap is provided with spaced parallel longitudinal corrugations or grooves having the desired shape. Preferably, this is accomplished by applying to the drum a layer of a preformed, vulcanized rubber cog pad having a smooth bottom surface with cogs or corrugations formed in the upper surface thereof. One or more layers of fabric are wound around the mandrel and laid into the grooves. A layer of sheet rubber of the desired thickness is then formed with a corrugated surface conforming substantially to the shape of the grooves on the mandrel. This is done by molding the sheet rubber in a press using a platen having the desired surface. This sheet is applied to the mandrel with the corrugations thereof engaging the fabric in the grooves of the mandrel and is then spliced. Over this layer, the layer of cord is wound in a helical manner with the convolutions thereof either contiguous or spaced as desired. On top of the cord layer another layer of sheet rubber having the desired corrugations impressed on the top surface thereof is next applied and spliced and a layer of fabric is wound around the corrugated top surface of the last named rubber sheet and forced into the corrugations. The surface is then wrapped with a vulcanized rubber pad having preformed corrugations corresponding to those in the top layer and the entire assembly rag wrapped to place the various layers under compression, after which the mandrel with the assembled layers is introduced into a vulcanizing chamber and cured for the necessary length of time. After vulcanization the outer wrapping is removed and the pad is stripped from the surface. The mandrel with the assembled layers which have now been vulcanized into an integral body is then mounted in a cutting machine and cut into parallel endless straps of the desired width. These straps are then removed from the mandrel, and the top and bottom pad layers stripped therefrom to expose the formed corrugations in the strap.

Modified forms of the invention are described in Figures 4 and S. In Figure 4 check strap 18a is formed with corrugations 27 on the inside surface thereof and is provided with cords 28 embedded between layers 29 and 30 of rubber and having top and bottom fabric layers 31 and 32. The method of manufacture may be similar to that described in connection with the modification of Figure 2 except that the top layer of rubber is not made with preformed grooves but is applied as a sheet and after applying the fabric layer 31 the assembly is rag wrapped and cured. In the form of the invention illustrated in Figure 5 check strap 18b is formed with angular grooves 33 and 34 on both the inner and outer surfaces of the strap with cord reinforcement 35 embedded between layers 36 and 37 of rubber and having top and bottom fabric layers 38 and 39. I The angular grooves are formed transversely and at an angle less than 90 degrees to the longitudinal axis of the strap. The method of manufacture is similar to that described in connection with the modification of Figure 2 except that the rubber layers are preformed with the angular grooves and the assembly is formed on a mandrel having grooves at the same angle. The inner layer may be formed with textile fibers 46 embedded or dispersed therein to increase stiffness of this layer without affecting flexibility. These fibers extend transversely and parallel to the longitudinal axis of the strap, and parallel to the picker stick contacting surface, as shown in Figresistance.

ure 5. If desired, both rubber layers may be formed with this fiber. These fibers may be omitted if desired.

Figure 6 illustrates in elevation the manner in which a single check strap of the type described and of the necessary width is utilized. Bracket 13 is mounted on lay beam 10 and has depending fingers 15, 16 and 17 which support the check strap 18. Picker stick 12 is engaged by the check strap at opposite sides of its arc of movement. Picker 42 is shown mounted on the end of the stick.

In Figure 7 another form of the invention is illustrated in which a plurality of relatively narrow check straps 180 are supported in superimposed relationship by fingers 15, 15 and 17 mounted on bracket 13 which is supported on lay beam 10 in a loom construction similar to that shown in Figure 6. Picker stick 12 on which picker 42a is mounted is illustrated at one end of its arc of movement. As illustrated, the necessary total width of the strap is divided among three narrow straps. The blow of the stick is shared by these straps and they all move in progressive increments with each blow. Any number of straps other than three may of course be used.

The rubber components of the check strap referred to above may be either natural rubber or any suitable type of'synthetic rubber, such as the butadiene-styrene copolymers (known as Buna-S), the bu-tadiene-acrylonitrile copolymers (known as Buna-N), the chloroprene polymers (known as neoprene), or the like, or blends thereof with each other or with natural rubber. It has been found desirable to increase the hardness of the rubber stock used in fabricating these check straps by incorporating finely divided textile fibers, such as cotton or rayon, in such a manner that the fibers are transverse to the longitudinal axis of the strap. This is accomplished by incorporating ground fibers, preferably having a length of not more than about one quarter inch, in the rubber stock by milling and then calendering the rubber to form a sheet. In the calendering operation the fibers will be aligned substantially in one direction and when the sheet is applied to the mandrel it is arranged so that the fibers are parallel to the longitudinal axis of the mandrel. As a result, the rubber material will have a greater hardness without any substantial increase in the stiffness of the strap. These fibers may be incorporated in either the outer or inner layers of the strap or in both, as shown for example, in Figure 5 for the purpose of illustration.

The fabric layers are desirable since they give increased wear and abrasion resistance and at the same time reduce the frictional resistance of the strap which would occur with an exposed rubber surface. Nylon fabric is preferred due to its wearing qualities and low frictional The weight of the fabric is subject to wide variation, 2 to 8 ounce square-woven fabric, bias laid being generally used. However, if desired the fabric may be omitted in certain cases. The longitudinal cord reinforcement is desirable since it imparts longitudinal strength to the strap. The cord may be composed of either cotton, nylon, or rayon, nylon cord being preferred because of its greater elasticity providing greater resisttions are subject to a wide variation.

ance to shock. The cord may be of any desired gauge, preferably in the range of to inch, and is usually treated to promote adhesion to rubber by impregnating with a suitable material, such as resorcinol-formaldehydelatex compound, well known for this purpose. The fabric is also preferably treated to improve adhesion to rubber and is generally skimmed with rubber on the side adja: cent to the rubber layer and without any mbber on the outer surface to avoid excessive friction. The cross sectional location of the cord is subject to a wide variation but in general it is preferred that the cord be positioned either in the midsection of the strap or between the midsection and the inner surface thereof. The fabric which is utilized is preferably square woven but is applied on a bias to give greater flexibility.

The depth and shape of the grooves or the corruga- In general, rounded teeth are preferred although the grooves or teeth may have a rectangular configuration. The spacing will depend upon the type of loom and the conditions of operation but in general the grooves should not be spaced less than one to an inch.

I claim:

1. A picker checking mechanism comprising a lay having a picker guide slot, a picker oscillatable within said slot, a check strap of elongated continuous endless flexible loop form surrounding said picker and having side portions adjacent opposite sides of said slot, a bracket rigidly attached to said lay at one side of said slot, said bracket having a plurality of depending fingers between which said check strap is supported with the side portions thereof frictionally engaging said fingers, said check strap being mounted for free movement upon engagement by the picker stick, the entire inner side portion of said strap being formed with parallel spaced corrugations extending transversely of its longitudinal axis whereby the strap will move intermittently in one direction as the result of successive blows of the picker stick.

2. A picker checking mechanism according to claim 1 wherein depending fingers between which the check strap is positioned are mounted adjacent both sides of the slot.

References Cited in the file of this patent UNITED STATES PATENTS 1,863,271 Handley et a1. June 14, 1932 2,216,999 Bacon Oct. 8, 1940 2,289,240 Bullard July 7, 1942 2,290,935 Bacon July 28, 1942 2,298,867 Case Oct. 13, 1942 2,315,763 Bacon Apr. 6, 1943 2,336,149 Freedlander Dec. 7, 1943 2,347,539 Brandon Apr. 25, 1944 2,435,749 Lesesne Feb. 10, 1948 2,480,316 Blair et al. Aug. 30, 1949 2,514,429 Waugh July 11, 1950 

